"Dear Ubuntu, for the last couple years life has been good. Every time I've shown you to a friend or family member, they've compared you to what they're familiar with--Windows XP or Vista, mostly--and by comparison you've looked brilliant. Yeah, your ugly brown color scheme was a bit off-putting at first, but once people saw how secure, simple, and reliable you were, the response was almost universally positive. But recently, things have changed ..."

Easy fix. Same can be done to /tmp if it's on its own partition to prevent executing programs that Firefox is told to "open" instead of download.

Even if this is not done, the user will need to go through the added trouble of giving the file executable permissions (or extracting the file first if in a UNIX permission-preserving archive format). The main problem I see is with .desktop files. Are desktop environments still treating them as "trusted" files that can be executed like programs even with no execute permissions? Hopefully not, because that's the most braindead idea, period... something you'd think came right out of Washington...

Also, anyone who does not know the basics of when and why to use their root password and where and how to get their software (from trusted repositories...) might as well just stick with Windows and get everything third-party as they've always done.